Slag screen and wall-cooling means



Dec. 16, 1930. H. J. KERR 1,785,350

SLAG SCREEN AND WALL COOLING MEANS Filed Jim. 4., 192 6 I I Ill) -7F/M/ INVENTOR W ATTORNEY;

Patented Dec. 16, 1930 UNITED STATES PATENT OFFICE HOWARD J. KERR, OF WESTFIELD, NEW JERSEY, ASSIGNOR TO THE BABCOCK WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION NEW YORK SLAG SCREEN AND WALL-COOLING MEANS Application filed January 4, 1926; Serial No. 79,126.

This invention relates to a water tube boiler in which some of the steam generating tubes are used both as a slag screen and as' a cooling means for the wall of a boiler furnace. The invention will be understood from the description in connection with the accompanying drawings, in which Fig. 1 is a vertical section through a Stirling boiler showing an illustrative embodiment of my .0 invention connected thereto; Fig. 2 is an en-.

larged section along the line 2-2 of Fig. 1,

and Fig. 3 is a section showing a small portion of Fig. 1 on an enlarged scale.

In the drawings, reference characters 1, 2

and 3 indicate the upper steam and water drums of a. Stirling boiler in connection with which my invention is illustrated, the lower drum being shown at 4, with banks of tubes 5, 6 and 7 connecting the drums. Water circulators 8 are shown between the front and middle drums. The usual baflles 9, 1O, 11 and 12 and superheater 13 are also indicated on the drawing. It is ,to be understood that the particular boiler illustrated in the drawings,

which constitutes no portion of my invention, is merely one of the many types of boilers with which my invention may be used. Side boxes 14 with tube connections 14' and 14." to the boiler may be provided, the connection 14 preferably extending through the furnace adjacent the side wallland the connection 14 being located outside the furnace.

A chain grate 15 is shown at the bottom of the furnace 16, but it is to be understood that stokers of other sorts may be used, and'that my invention is applicable either toa coalfired furnace or one in which powdered fuel is introduced by means of a fuel burner. The furnace illustrated on the drawing is provided with a rear wall 17, having an arch 18 extending above the end of the grate 15. A

row of tubes 19 extends from the steam and' water drum 1 across the upper portion of the furnace into proximity with the wall 17, and are bent around along the lower side of the wall 18 and terminate in a cross box 20 which extends transversely across the furnace. The

outer ends of the header 20 are connected by to tubes 21 (only one being shown in Fig. 1) on the outside of the furnace to the steam and water drum 2.

There may be one or more rows of tubes 19 and the tubes may be spaced across'the boiler, as desired, preferably being more widely spaced in either one or both directions than are the tubes 5 of the first bank of water tubes, in order to reduce the deposit of slag on the tubes of the first bank. The tubes 19 are held in place so that they can move longitudinally when they expand. In the illustrative embodiment, such holding means comprise lugs 23 attached to, tubes 19, as by autogenous welding, for instance, these lugs being connected to straps 24 that extend through spaces between special tile 25 in the wall 17. These straps 24 are connected at their other ends to cross pieces 26 that rest against buckstays 27, which also serve to hold the wall 17 in place. Fastening means- 28, similar to those above described, may connect the horizontal portions of the tubes 19 to the wall 18 or supporting members 29. The straps 28 extend from lugs 23' on the tubes to cross pieces 33 which rest upon the flanges of the I-beams The portions of the tubes 19 Which extend across the upper portion of the furnace 16 will serve as a slag screen to cool the slag sufficiently to revent the same from collecting 30 upon the tu s 5 of the boiler. The lower portions of the tubes 19 will also serve tocool the wall of the furnace, thus protecting the same against excessive temperatures. These tubes 19 being located where they will absorb much heat, serve as efiicient generators for steam which rises and enters the drum 1, while water passes from the drum 2 through the tubes 21 into the header 20, and then into the tubes 19, thus providing eflicient water to and steam circulation through these tubes.

Because of varying temperatures, the tubes 19 will expand and contract longitudinally and the arrangement which I have illustrated will permit this while, at the same time, keepmg the tubes 19 in proper relation to the wall 17 and arch 18.

I claim:

1 A water tube boiler, a furnace therefor having a chain grate stoker, an arch extend- 100 ing over'the rear of the stoker, and a vertical wall extending upwardly from the inner. end of said arch, some of the tubes of said boiler extending along the inside of said vertical wall and rearwardly beneath said arch.

2. A water tube boiler, a furnace therefor having a chain grate stoker, an arch extend.-

' ing over the rear of the stoker, a vertical wall extending upwardly from the inner end of said arch, some of the tubes of said boiler extending along the inside of said vertical wall and rearwardly beneath said arch, and means to hold said tubes against said wall and said arch, while permitting longitudinal motion to the tubes. v

3. In combination, a furnace having an arch with a horizontal portion, a vertical wall extending upwardly therefrom, a boiler drum disposed adjacent said wall, a bank of tubes connected to said drum and extending over the furnace in front of said wall, and a row of tubes extending along the inner faces of said arch and said wall and between the furnace and the bank of tubes.

- HOWARD J. KERR. 

